Skip the auto shop - Our mechanics make house calls

Symptoms of a Bad or Failing Ignition Cable

ignition cable

Bad or Failing Ignition Cable Inspection

by a top-rated mechanic at your home or office

The ignition cables, commonly referred to as the spark plug wires, are an ignition system component. While the vast majority of newer vehicles have now incorporated coil on plug ignition systems, ignition cables are still found on many road going cars and trucks. The ignition system works by firing off sparks at regularly timed intervals in order to ignite the engine’s fuel mixture. It is the job of the ignition cables to carry the engine’s spark from the ignition coil or distributor, to the engine’s spark plugs.

Spark plug cables are made of durable, low resistance materials that are able to withstand the high energy of the ignition system, as well as the harsh conditions underneath the hood. As they are link that carries the spark necessary for the engine to operate, when the spark plug cables have any issues they can cause problems that can affect engine performance. Usually faulty ignition cables will produce a few symptoms that can alert the driver of a potential issue.

HAVE SYMPTOMS OF CAR TROUBLE?
Get an $80 diagnostic
by a top-rated mechanic at your home or office.

Get a quote · Book an Appointment · Our expert mechanics come to you.

1. Decrease in power, acceleration, and fuel efficiency

One of the most common symptoms of an issue with the ignition cables is engine performance problems. The ignition cables carry the spark from the coil and distributor to the spark plugs so that engine combustion can occur. If there is any issue with the spark plug wires the engine spark can be disturbed, which can result in engine performance issues such as misfires, a reduction in power and acceleration, as well as a reduction in fuel efficiency. In severe cases bad cables may even result in engine stalling.

2. Check Engine Light comes on

Another symptom of a potential issue with the ignition cables is an illuminated Check Engine Light. Faulty cables can lead to engine misfires as well as excessively rich air fuel ratio, both of which can set off the Check Engine Light if detected by the computer. A Check Engine Light can also be set off by a number of other performance issues, so having the computer scanned for trouble codes is highly recommended.

HAVE SYMPTOMS OF CAR TROUBLE?
Get your car fixed at your home or office.

Get a quote · Book an Appointment · Our expert mechanics come to you.

3. Visible wear or damage to cables

Visible wear or damage is another symptom of an issue with the ignition cables. Old cables may dry out, which may lead to cracks in the insulation. There are also instances where the cables may rub up against a hot manifold or engine component, which may cause them to melt and burn up. Both of these issues may compromise the cable’s ability to transport the spark to the spark. This can lead to misfires and other performance issues, and in more serious cases may even lead to the cables shorting against the engine.

While many newer vehicles are now being manufactured without ignition cables, they are still found on a large number of road going cars and trucks, and play a vital role in engine performance. If you suspect that your vehicle may be having an issue with the ignition cables, have the vehicle inspected by a professional technician, such as one from YourMechanic, to determine if the cables should be replaced.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Still not sure about your car's issue?
Diagnose your car
What kind of issue are you experiencing?
Brakes are squeaking
Car is not starting
Car is overheating
Car is shaking (vibrating)
Fluids are leaking
Heating and A/C
Smoke or steam is coming out of the car
Warning light is on
Icon-warranty_badge-02

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

More related articles

The Traveler’s Guide to Driving in Malaysia
CraigBurrows / Shutterstock.com Malaysia is a popular destination for many tourists today. The country has amazing sights and attractions that you will want to explore....
Veteran and Military Driver Laws and Benefits in New Mexico
The state of New Mexico offers a number of benefits and perks for those Americans who have either served in an Armed Forces branch...
P0359 OBD-II Trouble Code: Ignition Coil I Primary/Secondary Circuit Malfunction
P0359 code definition The P0359 code indicates that a fault has been detected in one of the vehicle’s ignition coils, generally the number 9 coil. This code can also be associated...


Related questions

Q: Misfire in cylinder 2 and 6

It is possible that you have an ignition coil going bad. Once heat builds up, resistance in the ignition coils increase. If you have a weak coil, it will sometimes cause a misfire when it is hot. The misfires...

Q: Starter cable or starter not good

The information provided for your Dodge leads me to believe that you do indeed have a bad or loose connection between the battery and starter. It is likely that your battery terminals are not secured or perhaps have corrosion that...

Q: My gas mileage has dropped to 22 mpg, what could be the cause?

When a vehicle gets poor fuel economy, it's typically due to an electrical sensor that is faulty, such as the oxygen sensors, the air fuel ratio sensor, dirty fuel injectors, or the throttle body being dirty. Driving habits can also...